Process of making alkylene polyamines



of the amine. Moreover, the color and purity of diamme from propylene dichloride tional mols of alkylene imine react with a single so STATE P PROCESS F I. G ALKYLENE POLYS Alexander L. Wilson, Sharpsburg, Pa., assignor to Carbide and Carbon Chemicals Corporation, a corporation or New York No Drawing. Application May 24, 1941,

Serial N0. 395,025 I orr 10 Claims. (01. 260-583) Alkylene polyamines may be prepared by the reaction then involved may be illustrated in this condensation of alkylene dichlorides with aqueous manner, where n is an integer: ammonia. This method possesses the disadvan- N11i+n(iic --cum tage that the reactant are immiscible and the reaction must be carried out in equipment de- Ammonia olkyl iglmine signed for agitation under pressure. In addition i H N- (,1 LilltNilh-Cli uumn the mixture of aqueous ammonia and the amine z p0 yalkylono ol moiiio hydrochloride formed is corrosive and this prewhere N substimted alkylene nines are i ahazal'd masystem under Pressurewhlle volved, the first step of the reaction consists of e yields in the process are satisfactory. t the addition of one moi of the N-substituted imine separation of the free amme from the inorganic in a manner similar to the first reaction discussed salt formed after liberation of the amine from above. This reaction may h represented as folits hydrochloride is'd'iflicult and it involves losses lows; 4

the recover d lk polyamines are not of a 15 NHrHizb bH-R HzN-ClisCIllt-Nlilh uniform high standard. Finally. and more sig- It! i J J s I niiicantly. the process is unsatisfactory for mak- ,llgigiffiisiif, N iniiim mg higher alkylene polyammes such as propylene In those circumstances where one or more addi- According to the Dresent'invention, alkylene 0 polyamines are formed by the direct addition of mol of ammonia is pmbableilzat the an .alkylen m to ammonia This process is proceeds through the intermedia e formation 0 predicated on the discovery that alkyie mines the N-substituted monoalkylenc d amine and the w l react with ammonia with the breaking of subsequent addition of the N-substituted alkylene imine ring and the shifting of a labile hydrogen "W may be i fi i gg rg atom of the ammonia molecule to form an al I n atom 0 has in erme a e pr ue kylene polyamine In this process there are no lllnder these circumstances, the general reaction inorganic salts formed and the recovery of the followsalkylene polyamines is by a simple distillation. The nature of the alkylene polyamine formed de- 0 N|ii+o n,c -cu --in u.- pends on the alkylene imine employed and on the Z {1 conditions of the reaction. Alkylene imines which may be employed may be represented by where is (CHCI'IRNROMH'QHS the formula: (CI-lzCI-IRNRrhH.

' and Q: is (CHaCHRNRrMH; m. p, and q and 0 or integers and are related by the equation where R is hydrogen or an alkyl radical, and R1 m+p+qml is hydrogen or a monovalent hydrocarbon radical. e V such as an alkyi, cycloalkyl, aryl, or araikyl n being integerradicaL The term "alkylene poiyamme' as used herein where 31 is hydrogem the general reaction may includes both monoalkylene diamines and polybe represented as follows, showing th addition 1 alkylene polyamines irrespective of whether such t nine t th ammonia molecule; compounds are of straight chain or branched one mo] of e chain configuration and whether such compounds c -cn-n uN-cuoum-Nn Nm+m 7 as have terminal substituted amino groups; or

NH terminal primary amino groups. all as illustrated Ammonia alkylono iminc uionoalkyicuc diamine b 7 Under certain conditions, to be discussed later, The characterof the alkylene poiyamine i'orrned more than one moi of the alkylene imine may redepends on the ratio or the ammonia to the alact with a single moi of ammonia and the general to kylene imine. in general, a high molar ratio of ammonia to imine, for example, a value of 10 to 1, will favor the formation of the monoalkylen diamine, whereas lower molar ratios oi ammonia to imine, for instance, 3 or 4 to 1, will promote the production of dialkylene triamines and trialkylene tetra-amines as well as monoalkylene diamines. As a rule, it appears that an excess of ammonia is necessary if it is desired to prevent the formation of relatively large amounts of high boiling polyalkylene polyamines. The reaction is catalyzed by the presence of an excess of water and the reactants may therefore be added in the form of their aqueous solutions.

Reaction temperatures may be between and 200 C., a slow but appreciable reaction occurring at room temperatures. In general, however, somewhat elevated temperatures are preferred to accelerate the reaction and, in such case, the

reactants must be enclosed in a pressure resistant.

vessel-to retain the volatile ammonia.

The alkylene polyamines, especially the lower members of the series, are useful to neutralize acids. to inhibit corrosive tendencies, and in the preparation of surface active agents by their condensation with fatty acids. In addition, the higher boiling polyalkylene polyamines, because of their high absorptive capacity for water vapor and acid gases. may be used in processes for purifying and dehydrating gases.

Alkylene imines which may be employed in the process of this invention include unsubstituted alkylene imines, such as ethylene imine, propylene imine and butylene imine. as well as N-substituted alkylene imines. 'N-substituted alkylene imines which may be used include N-propyl, N- butyl, N-phenyl and N-cyclohexyl ethylene imine. These imines are liquids of moderate boiling points having strong, ammoniacal odors. The alkylene imines may be formed by known reactions, such as by heating aminoethyl sulfate with aqueous sodium hydroxide, in the case of ethylene imine.

The production of azo-tris-ethylimino benzene, N(C2H4NHC6H5)3, by the reaction of N-phenyl ethylene imine with ammonia is typical of one class of the products formed when N- substituted alkylene imines are employed and the following examples will serve to illustrate the practice of the invention as applied to the unsubstituted alkylene imines.

Example 1.Ethylene diamlne was prepared by the reaction of 99 grams of a 44% aqueous solution of ethylene imine (containing 1.0 mol of the imine) with 304 grams of 26% aqueous ammonia solution (containing 5 mols of ammonia) in an autoclave at a temperature of 130 C. and under a pressure of 200 to 300 pounds per square inch. After two hours the charge was cooled and fractionally distilled at atmospheric pressure. The yields of alkylene polyamines were ethylene diamine 27%, diethylene triamine 32%, trlethylene tetramine 15%. tetraethylene pentamine 11% and residual higher amino products 15%.

Example 2.--Propylene imine was prepared by the reaction of amino-isopropyl sulfate with aqueous sodium hydroxide as a liquid boiling at 65 C.

Propylene diamine was prepared byreacting 30 grams (0.5 mol) of propylene imine with 327 grams of 26% aqueous ammonia solution (containing 5 mols of ammonia) in a 500 cc. stainless steel autoclave. The mixture was heated at a temperature of 110 to 120 C. under a pressure of 100 to 200 pounds-for two hours after which the mixture was cooled and refluxed until free of excess ammonia. The reaction mixture was then fractionally distilled. 'I'he first cut was taken in the range of 99 to 100 C. and consisted mostly of aqueous ammonia. The second cut was taken between 100 and 102 C., weighed 47 grams and contained 0.69 gram of propylene diamlne. The third cut was taken between 102 and 122 C., weighed 65 grams and contained 21.3 grams of propylene diamine. The fourth cut taken at to 220 C. consisted of 9 grams of dipropylene triamine. The distillation was then halted, the still residue of higher polyamines weighing only 3 grams. Based on cuts 2 and 3 the yield of propylene diamine was 59% and of dipropylene triamine 27% on the propylene imine basis.

Purified dipropylene triamine was found to have a boiling point of 102 to 103 C. at 10 mm. of mercury pressure, a specific gravity of 0.875 at 20/20 C. and a refractive index of 1.4670 at 20 C.

Other modifications of the process will be apparent and are included in the invention as defined by the appended claims.

I claim:

l.-Process for making alkylene polyamines which comprises reacting ammonia with a 1,2- alkylene imine.

2. Process for making alkylene polyamines which comprises reacting ammonia with a 1,2- alkylene imine in the presence of water.

3. Process for making alkylene polyamines including a substantial quantity of a monoalkylene diamine which comprises reacting ammonia with a 1,2-alkylene imine in the molar proportion of at least three mols of'ammonia per mol of the alkylene imine.

4. Process for making ethylene polyamines including a substantial quantity of an ethylene diamine which comprises reacting an aqueous so lution of ammonia with ethylene imine in the molar proportion of at least three mols of ammonia per mol of the ethylene imine.

5. Process for making alkylene diamines whic comprises reacting ammonia with a 1,2-alkylene imine in the molar proportion of at least ten mols of ammonia per mol of the alkylene imine.

6. Process for making alkylene polyamines having at least one terminal hydrocarbon radical which comprises .reacting ammonia with a 1,2- alkylene imine substituted at the nitrogen atom with a monovalent hydrocarbon radical.

7. Process for making ethylene diamine which comprises reacting ammonia with ethylene imine.

- 8. Process for making propylene diamine which comprises reacting ammonia with propyleneimine.

9. Process for making alkylene polyamines including substantial quantities of a dialkylene triamine and a trialkylene tetramin which comprises reacting ammonia with a 1,2-alkylene imine in the molar proportion of from one to four mols of ammonia per mo1 of the alkylene imine. i

10. Process for making ethylene polyamines including substantial quantities of diethylene tri amine and triethylene tetramine which comprises reacting anaqueous solution of ammonia with ethylene imine in the molar proportion of from one to four mols of ammonia per mol of ethylene imine.

, ALEXANDER L. WILSON.

' CERTIFICATE OF CORRECTION. Patent No. 2,51 ,750. May 11, 19h

' ALEXANDER L. WILSON.

It is hereby certified that error eppears in the printed specification of the above numbered patent requiring correction as follows: Page 1, sec- 0nd column, line .55, for "and" before"0" rea "are": and that the said Letters Patent should be read with this correction therein that the same may confolmto the record of the case in the Patent Office.

Signed and sealed this 22nd day of June, A. D. 19h5.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

